The disclosure of this invention will focus on its application in the traditional telephone system. This is done for the sake of clarity and brevity, since describing the application of this invention in each of the other telecommunication systems would be needlessly tedious. It will become clear to a person reasonably skilled in this art that the methods described in this disclosure can be applied similarly to any communication system, including wireless communication systems including those using radio connections.
Several methods are currently in use for establishing a telephone conference call. These include:                1. Prearrange a time when each conferee will dial a specified phone number to join a conference call. At the prearranged time, as each conferee makes a connection to the specified phone number, they are automatically joined to a conference call that is already operational before any conferees have joined.        2. A call administrator manually dials each target conferee, placing each contacted conferee on hold while attempting to contact the remainder of the target conferees. Then, when all conferees have been contacted, the call administrator causes them all to be simultaneously bridged into the conference call via features available in a local PBX or telephony switch system.        3. A method described in 2 above, wherein a computerized system replaces the call administrator, performing the same functions automatically.        
In method 1 (above), the process is semi-coordinated in that a prearranged time is used as a target connection time for each conferee. One problem with this approach is that it relies on the conferees to remember the exact prearranged time of the call. It also relies on the expectation that each of the conferees will initiate their connection to the conference call at the same time (any delay by one or more conferees to initiate dialing will delay the effective start time of the conference call). This approach also assumes that all of the target conferees' time clocks are precisely synchronized (even a few minutes of difference between clocks can delay the effective start time of the conference call). Another disadvantage of this approach is that, intentionally or unintentionally, uninvited participants can be connected into the conference call at any time during the call. One advantage to this approach is that the process of initiating the conference call is parallel in nature. This can reduce the amount of time required to connect all of the conferees to the conference call. Unfortunately, this approach's parallel activity is uncoordinated and relies on the memories and attentiveness of each of the target conferees. Thus, problems remain with this approach.
In method 2 (above), the manual process of serially dialing even a few conferees is tedious, time consuming and error prone. If a significant number of conferees are included, this process becomes completely impractical due to the amount of time required to contact the entire list of conferees before the conference call can start. One benefit of having a person manually dial each of the target conferees is that the person has the ability to detect and correct errors on the conferee list (wrong or disconnected phone number, etc.). This person can also determine in real time whether the correct person has answered the phone, whether or not an answering machine or voicemail has been reached, whether the connection time has become unreasonable or unusually long and, finally, whether or not the target conferee accepts the invitation to the conference call. Another advantage of having a person manually dial each target conferee is that the person can redial the conferee if their connection is lost and it is known that the conferee wishes to continue to participate in the conference call. Thus, problems remain with this approach.
In method 3 (above), the automation of the dialing process removes the tedious dialing task from a human, and reduces the time required to contact the entire list of conferees. However, the dialup process is still serial, thereby incurring the unavoidable accumulation of delays associated with contacting each conferee.
Many systems exist for automatically initiating and controlling conference calls. Even the most automated of these systems, however, invariably uses the same basic process to initiate a conference call. The basic process includes the serial steps of:                1. Dialing a conferee (from among those found on a list of target conferees).        2. If contact is made with the target conferee, making a connection between that conferee and the pending conference call.        3. After these first steps are completed, the process is repeated for the next conferee on the list.This continues until all of the target conferees have been contacted and connected to the conference call. At this point, the conference call can begin.        
As described below, this serial dialup process has several disadvantages.
The first disadvantage of the serial dialup process is that the conference call is stalled (with participants waiting on hold) while the remaining conferees are being connected to the call. Since the time required for each connection to a conferee may be several seconds (typically 5 or 6 seconds before the dialed number even begins ringing), when the quantity of conferees exceeds 20 the conferee who was contacted first is required to wait up to 2 minutes before the call becomes operational. This may seem insignificant, but as the quantity of conferees rises, the delay associated with contacting all of the conferees rises proportionally. When a massive list of conferees is used (as occurs when a conference call is used to disseminate a corporate announcement), this delay becomes burdensome. For instance, if a conference call is intended to reach 5000 employees of a company, the cumulative connection delay could exceed 7 hours (assuming an average connection time of 5 seconds per conferee). This makes the serial dialup approach impractical for this application (or any other mass telephony conference application).
A second disadvantage of existing conference call initiation processes is that statistics are not kept that can be used to make subsequent conference calls to the same conferees more efficient. For instance, if a target conferee changes their phone number, time is wasted unsuccessfully attempting to contact them at their old phone number. Not only does this waste time and resources, it can potentially annoy someone who has since acquired the old phone number.
Yet another disadvantage of existing conference call initiation systems is the inherent risk of using a single dial-out source (telephony switch or PBX). Should this switch fail (or its connections to the PSTN fail), the successful completion of the conference call becomes impossible.
Another significant disadvantage of current conference call initiation systems is that there is no mechanism for determining whether a conferee, who has disconnected from the conference call in progress, desires to be reconnected to the call.
From this explanation it can be seen that a method and article are needed for reducing the amount of time required to connect an entire list of target conferees to a conference call. It can also be seen that there is a need for a conference call system that is not vulnerable to a failure of a single telephony switch or that switch's network connections. Further, it can be seen that there is a need for a conference call system that automatically gathers and analyzes statistics of a conference call in order to improve the efficiency of the conference call initiation process for subsequent conference calls. It can also be seen that there is a need for a conferencing control system that can determine whether a connection should be joined to the conference call based on predefined parameters and detected conditions. It can finally be seen that there is a need for a conferencing control system that can determine whether a disconnected conferee should be reconnected to the conference call by either automatically out dialing to the conferee, or by allowing the conferee to dial a predefined phone number, and after being revalidated, be reconnected to the call.